We created fusion chimeras between GR and other nuclear receptors that manifest ligand dependent cytoplasmic/nuclear translocation for the chimeric receptor in response to the heterologous ligand. The approach has been successfuly developed for the retinoic acid receptor (RAR), the estrogen receptor (ER), and the progesterone receptor (PR), and the thyroid hormone receptor (ThR). We developed cell lines which express fluorescently tagged versions of the receptor chimeras, and shown that U.S. water supplies are heavily contaminated with chemicals that have glucocorticoid and androgen activity. We believe that this approach can be generalized to many members of the nuclear receptor super-family, opening a new avenue for characterizatuib of water supply contaminaton.